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04-26-2011, 03:08 AM   #91
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Post away ... it's nice to see the pictures. You can always use the live mode in the meantime if you can supress the inner purist in you

I have found various fitting shims in old full-frame cameras (Canon a1 series, probably others). Their focusing screen shims are sometimes exactly 2x the size of the pentax ones - all you have to do is to cut it in half.

QuoteOriginally posted by aliasant Quote
I was out trying my Nikkor 85mm f1.8 today. Trying to get some backlit shots.
I did use a hood and I never got the sun directly into the lens but on some of the shots you can clearly see the effect.

Unfortunatly I havnt got my new thinner shims to go with my Katzeye Focusscreen so hitting focus was quite hard. The shims that Pentax ships with the K5 is 0.4mm thick and apparently those that have ordered thinner shims to adjust this has ended up using 0.2-0.25mm shims to get correct focus. I will get mine on Monday and I hope it helps. If not maybe I should stop photographing or get one of those new lenses that can do the focusing for me ?

Heres the flickr site with the images. Warning! No supershots but that was never the intent. ( read: the photographer su#¤s)
Nikkor 85f1.8-Spring1034 | Flickr - Photo Sharing!

Dont want to spam here with that many pictures but I can post one to show some back lighting.
I missed focus on this one (again) but it turned out nice anyways. Maybe just because I missed?


04-27-2011, 11:04 AM   #92
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QuoteOriginally posted by vw_michael Quote
Post away ... it's nice to see the pictures. You can always use the live mode in the meantime if you can supress the inner purist in you

I have found various fitting shims in old full-frame cameras (Canon a1 series, probably others). Their focusing screen shims are sometimes exactly 2x the size of the pentax ones - all you have to do is to cut it in half.
I did get new shims and Im currently using 0.25mm and its almost perfect but perhaps I need to step up to 0.3. Im at the countryplace taking pictures but I forgot to bring the shims so I will have to wait.
Im even considergin removing the Katzeye screen when I get back home.

Didnt bring that 85mm f1.8 Nikkor but I did bring the 35mm f2 and its a great lens.

Heres one I took wide open today.
Father and Son
05-15-2011, 03:22 PM   #93
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Does an el-nikkor lens count here?
06-17-2011, 07:30 AM - 3 Likes   #94
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Adapting Nikkors - My Way

Mounting Nikkor Lenses on a K Mount Camera


For quite a while I have intended to describe my experience with adapting Nikkor lenses for use on Pentax K mount cameras, both the film and digital versions. A couple of months ago, I did get around to taking pictures of the lenses and the adaptor I designed. Now here is the description.

A Few Preliminaries

I have adapted four Nikkors. All are prime lenses. Three of the four are non “AI” Nikkors.

(A bit of history. From 1959 and the introduction of the Nikon F, the interchangeable lenses had an aperture coupling prong – the “ears” on the rim at the rear of the lens. On pre-1977 cameras, it was necessary to "index" the lens to the camera's meter each time a lens was mounted. This entailed rotating the lens to its largest aperture and back. This action ensured that the meter was properly calibrated. In 1977, Nikon introduced Automatic Indexing [AI] linking lenses directly to the meter without having to dial in aperture information. Nikon accomplished this by adding a coupling ridge on bottom of the aperture ring. Older, non-AI lenses could be modified to be AI either by Nikon or many independent camera technicians.)

With the one AI lens I have modified, I removed the coupling ridge on the back of the lens. I did this as the ridge prevented the lens from seating flat on the Pentax camera’s lens mounting surface.

My first attempts to modify Nikkors for use on a Pentax simply involved trying to insert the three prongs of the Nikon mount into the three receiving notches of the Pentax mount. This generally worked but there were issues. These were:

1. The amount of rotation was very limited – about 1.5cm or .5 inch. The lens always seemed to be at risk of falling off if the camera were bumped for instance.
2. The Nikkor locking notch did not line up with the locking pin of the Pentax mount.
3. On some of the Nikkors, the back of the lens – the aluminum section which surrounds the rear lens element, has the three mounting prongs and is screwed onto the lens body – is flush with the back of the aperture ring. On other Nikkors , the back of the aperture ring is higher than the aluminum back. This leads to problems.
4. The distance between the back of a lens and the film or sensor plane of the camera is known as the registry distance. On Pentax lenses (both the old M42 as well as the K mount lenses) the distance is 44.6mm while on Nikkors it is 46mm. The good news for Pentaxians is that Nikkors mounted on a Pentax will focus at infinity without needing any optics to change the plane of focus. Because of the different lens registries, however, the distances marked on the Nikon lens from closest focus to infinity will be incorrect. Accurate focus at infinity will be achieved when the marked distance is well short of infinity.

Before I realized that there were differences between the backs of Nikkors as noted above, I thought the solution to creating a notch for the Nikkor lens to mate with the Pentax body was simple. Just drill a small hole in the aluminum back at the appropriate spot and the Pentax pin would mate with the hole and hold the lens in place. This action worked for the first lens I modified (the Nikkor-P 105mm f2.5) but, on the other three Nikkors, the protruding back of the aperture ring prevented the locking pin on the camera from mating with the drilled hole. The pin is not long enough.

I discovered a second problem caused by the protruding back of the aperture ring on some Nikkors. The distance from the aluminum lens back to the camera’s lens mounting surface prevents the necessary electrical shorting of the Pentax’s lens information contacts which is necessary for “catch-in-focus” shooting.

My Solution

Upon careful examination of various Nikkors I thought of a fairly simple solution to all of the issues mentioned above. A narrow metal ring attached to the aluminum back of the Nikkor extending from the ridge below the mounting prongs to the inner edge of the back of the aperture ring would solve two issues. Namely, to correct the registry difference between Nikon and Pentax; and, create the electrical shorting necessary to permit catch-in-focus. Further, if a notch were included in the metal ring that lined up with the Pentax locking pin when the lens was mounted, the lens would be held much more securely in place.

I chose to have the rings made from stainless steel 1mm thick. The outer diameter of the ring is 5.6cm (56mm); the inner diameter, 4.7cm (47mm). There is also a locking notch which is 2mm wide and 3mm deep. (See photo.) I decided to use a glue to hold the ring in place as this would not require making any changes to the Nikkor and thus allowing its restoration to Nikon use if desired. (See photo.)

Further Observations

In various online discussions I have read about using Nikkors on K mount Pentaxes, there have been differences about where the “top” of the lens should be. Given that there are three ears on the lens and three notches on the camera, the Nikkors I am familiar with can be mounted in any of three orientations. The aperture information can be set at roughly the 10 o’clock, at 2 o’clock or at 6 o’clock positions when facing the camera.

I much prefer the 10 o’clock orientation. (See photo.) That puts the aperture information on the right hand side of the camera as you are taking pictures. It is thus on the same side as most of the controls including the LCD panel. For me this “off center” lens orientation is preferable to it being at the 12 o’clock position. The built-in flash overhang makes seeing aperture marking difficult.
Some may have noted that the stainless steel ring I have chose is only 1mm thick while the difference between Nikkor and Pentax lens registry is 1.4mm. My experience is that the added 1mm ring results in the viewfinder manual focus indicator lighting when the object is at infinity and that is also where the lens focus ring is set. I suspect the explanation is threefold. There is some tolerance in the camera choosing “perfect” focus. The cutting of the inner and outer ring diameters in the sheet of stainless steel added slightly to the thickness. The glue has added a bit of thickness as well. In any event, the 1mm thickness of the ring provides me with excellent focusing results.

Finally, some care is needed in setting the ring and getting the locking notch in the right place. Initially, I simply noted where the notch should be by mounting the lens and marking the position of the pin on the lens barrel. I failed to consider that the extra thickness of the lens with the ring would prevent the lens from turning as far when mounting. Set the ring slightly short of the mark where the lens would mate with the pin without the ring.

Hope this proves useful.

(In addition to the photos of the stainless steel ring, the glue and the Micro-Nikkor mounted on my K20D, there are shots of the following Nikkors with the ring added:

Nikkor-O 35mm f2.0 [2 photos]
Nikkor-S 50mm f1.4
Micro-Nikkor-P 55mm f3.5
Nikkor-P 105mm f2.5)


Richard


________________________________________



Last edited by rrodgers; 03-21-2015 at 10:30 AM.
08-04-2011, 06:28 PM   #95
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Very interesting approach - thanks for sharing. I'll try to make a ring like that to experiment.
08-23-2011, 08:31 AM   #96
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Nikkor 28mm f3.5 non-AI Comments

Hello everyone. Thought that I would take a little time to share my thoughts about my k-x and a Nikkor lens I recently purchased. I have a Nikkor-H 28mm f3.5 Nippon Kogaku, non-AI.

What started me on this was a) this thread; and b) a thread over at DPreview forums about 5 years back regarding the ability to put Nikkor lenses on Pentax bodies. This whole idea is very pleasing to me, since I used to very much enjoy my Nikon Photomic T with several excellent Nikkor lenses back in the 1970s. Back then, everything was manual; moreover, I considered myself fortunate to have through-the-lens-metering. Wooo!

What I should like to share:
1. Because it is a small non-AI lens, it mounts more securely than I thought it would without any modification whatsoever. By turning it to about the 2:00 position it fits fairly snugly. Not so good that one does not have to ever worry about it, but decent enough. Just to make sure, when I adjust the aperture ring and/or the focus ring, I use another finger to gently push the lens in a clockwise direction so as to maintain the mount.
2. Of course, it must be used in a manual fashion and the green button. Honestly, I enjoy all this because it takes back this old man to the 1970s when I used my film Nikon back then. To me there is something pleasant about taking my time to plan, compose, and focus a picture.
3. In my testing, I find that this lens, even at f3.5, takes some practice to focus in low light situations. I find that it is more suited to outdoor pictures, often at f8 and infinity focus.
4. Out of the 150 or so pictures that I have taken so far, there is a tendency for my k-x to underexpose the pictures. But, they can be corrected either by a wb adjustment prior to taking the picture or in post processing.
5. When I get good focus, I find the lens to be pretty darn sharp even at f3.5. There is some pf, and some softness at the borders, but in the center, it is very nice.
6. As I mentioned in 3. above, I consider this lens as more of an outdoor f8 lens when the light is good. You can use it indoors in poor light, but for this old man, it is hard for me to get good focus a reasonable percent of the time.
7. At this point, the only comparison that I can do is with my 18-55 kit lens at 28mm. While I am still testing, I find that with iso400, good focus, the Nikkor at f5.6 on up is sharper than the kit lens. But, I will say that the kit lens is not bad. At 28-35mm, f8, the kit lens is a value hard to beat.

In conclusion, I should like to say that I am glad I got the lens ($35 at keh in bgn condition) and look forward to more picture taking with it. Perhaps I shall try to get a 50mm f1.4, my old favorite, sometime as well.

Late yesterday afternoon, I took this pic in the front of my yard facing west toward Sierra Blanca peak. It has been resized and post processed a tad.

11-05-2011, 02:21 PM   #97
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Nikkor50/1.4 photos:
https://picasaweb.google.com/111102833818394930252/Nikkor50f14

rrodgers, and all,
I need the metal ring as you have in the photos, to insert into ai and ais lenses.
Where can i get them?

Working on nikkor 180/2.8ED, 400/5.6ED, and PC 28/3.5.
Thanks.

11-06-2011, 08:45 AM   #98
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Hello hoanpham,

The metal ring described above is something I designed and had made for me. I was fortunate in that my partner's brother works in a metal fabrication shop and he produced four rings for me at no cost. I have not tried pricing the rings if made commercially. I suspect they would cost in the $30-45 range but that is a guess. A few made at the same time would no doubt reduce the per unit cost.

Richard
11-06-2011, 12:42 PM   #99
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Hi Altovintner:

Are you referring to the thread @ DPReview started by Carpents? That thread got me started buying Nikkor glass for my Pentax body too. Eventually that lead me to a Nikon body. This shot is with an AIS 50mm f/1.8 E-Series lens. The E lenses are looked down upon by some of the snootier members of the Nikon community, but the lenses deliver and are inexpensive. This 50mm often goes for $25. They are said to not have the build quality of regular Nikkors, but my copy (>30-years old) still looks and behaves like new. I haven't yet tried to mount it on my K20d, but here is a shot with it on a FF body, @ f/22.

11-08-2011, 04:23 PM   #100
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QuoteOriginally posted by Jewelltrail Quote
Hi Altovintner:

Are you referring to the thread @ DPReview started by Carpents? That thread got me started buying Nikkor glass for my Pentax body too. Eventually that lead me to a Nikon body. This shot is with an AIS 50mm f/1.8 E-Series lens. The E lenses are looked down upon by some of the snootier members of the Nikon community, but the lenses deliver and are inexpensive. This 50mm often goes for $25. They are said to not have the build quality of regular Nikkors, but my copy (>30-years old) still looks and behaves like new. I haven't yet tried to mount it on my K20d, but here is a shot with it on a FF body, @ f/22.
Hello Jewelltrail. Yes, I am indeed referring to the DPReview you referred to.

And --- congrats and kudos for a great pic! Thanks for sharing.
11-16-2011, 12:36 PM - 1 Like   #101
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Micro Nikkor for Slide Copying

I have started copying my 35mm slide collection. While I have an Epson Perfection 700 Photo scanner, I have never found the results of scanning 35mm slides with it to be really satisfactory. (Its prime use has been to scan medium format black and white negatives.)

I recently decided to try to copy some of my slides using a Micro Nikkor 55mm f/3.5 lens. (Please see above post about modifying Nikkor lenses for use with my Pentax K20D.) I am using the Micro lens with the Nikon ES-1 Slide Copying Adapter. As this adapter is designed for use with a 35mm - "full frame" - camera, some additional extension is required between the front of the lens and the adapter in order not to crop the slide with the APS-C sized sensor. I bought a 24mm extension tube from Hong Kong which does the job perfectly.

I've been practicing with about 150 slides so far and am quite pleased with the results. Once I have finalized the lighting method; have the camera/lens/adapter rig set up on a tripod; and the slides well arranged for copying, I expect to be able to copy three or maybe four slides per minute.

All slides have been copied using raw and require some sharpening, possibly cropping and other adjustments. I use Adobe Camera Raw and quite enjoy the processing. And now I have only about 2000+ slides to go!

Here are a few examples of digitized slides from the past 20 years:





















Last edited by rrodgers; 11-16-2011 at 12:47 PM.
02-06-2012, 08:14 AM   #102
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Sigma 8mm F3.5 EX DG Fisheye SLD

Hi,

I got Sigma 8mm with a Nikon D80. I would like to use this lens on my K5. The adapter with lens is not good solution because it is not 1:1.
The adapter without lens is not good because I need infinity.
Can you offer any simple solution to use the lens on my Pentax?

Br, Zoli
02-06-2012, 09:58 AM   #103
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QuoteOriginally posted by barez Quote
Hi,

I got Sigma 8mm with a Nikon D80. I would like to use this lens on my K5. The adapter with lens is not good solution because it is not 1:1.
The adapter without lens is not good because I need infinity.
Can you offer any simple solution to use the lens on my Pentax?

Br, Zoli
There's not really a way to adapt a modern AF lens (I'm assuming your Sigma is one) from Nikon to Pentax mounts, unfortunately.
06-18-2015, 08:20 AM   #104
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Might have to revive this Zombie. Just scored a Nikkor 28 2.8 ais (Ebay £50) Looks in great condition. I will report back.

Last edited by doggy1972; 06-18-2015 at 08:54 AM.
05-11-2017, 09:52 PM - 1 Like   #105
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Almost 2 years without any posts, so here is a shot with a K-s2 and a Nikkor 105/2.5 Ai-S

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